Way ahead of you, Wayne. You may recognize some of the text on that page...

BTW, I would like to add some rdoc to the classes but I don't know how to do that for methods that are part of the C extension and have no ruby equivalent. I'll look into the rdoc syntax and see if there's a way I can achieve that. Any problem with that?

cr

On May 11, 2010, at 6:09 PM, Wayne Meissner wrote:

> Well, now that you are wise in the way of pointers, please go ahead
> and fix the damn page :-)
> 
> If something on the wiki doesn't look right, fix it - its a wiki after
> all.  (and if your changes aren't right, in theory someone else will
> rip your stuff out ... ad infinitum).
> 
> 
> 
> On 12 May 2010 08:59, Chuck Remes <cremes.devlist@mac.com> wrote:

>> I'll make the modifications for #1 and #2.
>> 
>> The text at the top (#3) was put there by someone else. I just added to the page. It didn't look right to me, but it's been there for a while so I didn't touch it. :)
>> 
>> cr
>> 
>> On May 11, 2010, at 5:33 PM, Wayne Meissner wrote:
>> 

>>> It looks pretty good.
>>> 
>>> A couple of nits:
>>> 
>>> 1) The LibC module can just use:
>>>   ffi_lib FFI::Library::LIBC
>>> 
>>> ffi knows that means "whatever the libc on this system is supposed to
>>> be", since its a pretty common library people want to map in, and the
>>> name differs across platforms (e.g. on linux, its libc.so.6, macos is
>>> libc.dylib, windows is msvcrt.dll, aix is something weird, etc.
>>> 
>>> 2) The first arg to MemoryPointer.new can in fact be either a symbol,
>>> or anything that responds to #size.
>>> e.g.
>>>  class S < FFI::Struct
>>>    layout :i, :int
>>>  end
>>>  FFI::MemoryPointer.new(S, 1, false)  # Will allocate space for one
>>> instance of S, without clearing the memory first
>>> 
>>> 3) The bit at the top about copying pointers is ... confusing.  A
>>> pointer is merely a Fixnum that holds a native memory address, so
>>> there is no need to do anything special to "copy" a pointer - just
>>> assign it to a like you would any other Fixnum.  Think of "Pointer" as
>>> "fixnum with methods to read/write the native memory at the address".
>>> 
>>> The example:
>>> 
>>> b = MemoryPointer.new(:pointer).write_pointer(some_pointer.read_pointer)
>>> 
>>> Doesn't do what you think.  It reads a pointer from the memory
>>> pointed-to by some_pointer, allocates a new chunk of memory, and
>>> writes that pointer value into that memory - it doesn't copy the value
>>> of some_pointer to a new pointer.
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> On 12 May 2010 02:02, Chuck Remes <cremes.devlist@mac.com> wrote:

>>>> I just wrote an update to the wiki page on pointers at http://wiki.github.com/ffi/ffi/pointers
>>>> 
>>>> I'd appreciate it if someone more knowledgeable would check it over (the bottom section under the sub-heading) and verify that what I wrote is correct. It seems to be working for me but I've been wrong before! :)
>>>> 
>>>> cr
>>>> 
>>>> 

>> 
>>